Meldrum, Jeff; Hilton, Charles E. (2011-06-27). From Biped to Strider: The Emergence of Modern Human Walking, Running, and Resource Transport. Springer Science & Business Media. Can be read here.
STS 14 is a fossilized partial skeleton of the species Australopithecus africanus. It was discovered at Sterkfontein, South Africa by Robert Broom and John T. Robinson in August 1947, and is estimated to be about 2.5 million years old. Some scientists have proposed that STS 14 may have come from the same individual as STS 5 though that fossil is considered only 2.15 million years old.
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"Australopithecus africanus". Australian Museum. Can be read here.
Johanson, Donald; Edgar, Blake (2006). From Lucy to Language. Simon & Schuster. p. 148.